The story of Sir Isaac Newton and the falling apple is one of the most famous anecdotes in science. The young Isaac Newton was sitting under an apple tree in his garden when a fruit fell on his head, and in a sudden stroke of brilliant insight, he came up with the theory of gravity. The story is most likely embellished—at least the part where the apple hits Newton’s head—but there is also some truth to it.

The first written account of the apple falling incident appears on the notes of John Conduitt, who was Newton’s assistant at the Royal Mint and husband to Newton's niece. In 1726, the year of Newton's death, John Conduitt described the event:

In the year 1666 he retired again from Cambridge to his mother in Lincolnshire. Whilst he was pensively meandering in a garden it came into his thought that the power of gravity (which brought an apple from a tree to the ground) was not limited to a certain distance from earth, but that this power must extend much further than was usually thought. Why not as high as the Moon said he to himself & if so, that must influence her motion & perhaps retain her in her orbit, whereupon he fell a calculating what would be the effect of that supposition.

The tree from which the famous apple is said to have fallen, in the grounds of Woolsthorpe Manor in Woolsthorpe-by-Colsterworth, in Lincolnshire, England. Photo credit: Dun.can/Flickr